The aim of this study was to evaluate the effects of adding conjugated linoleic
acid (CLA) to boar diets on semen production and characteristics, the fatty
acid profile of spermatozoa, and on testicle and boar carcass parameters. Ten
lean-type terminal-line (Yorkshire × Landrace × Pietrain) adult boars were
randomly assigned to one of two treatments: (1) a control diet and (2) the
same diet with 1 % CLA. The research was conducted in Mexico, and animals
were exposed to ambient temperatures between 13.5 and 26.3 °C. Boars
were ejaculated twice per week during a 12-week period to examine semen
production and characteristics. The results suggest that supplementation of
boar diets with CLA did not affect the spermatozoa fatty acid profile, semen
volume, sperm concentration, viability, or motility, nor did it cause abnormal
sperm morphology. Compared to controls, boars fed a CLA diet had a higher
seminal pH and increased backfat thickness. In summary, this study indicates
that CLA addition in boar diet does not change the semen characteristics or
fatty acid profile of spermatozoa; however, it increases backfat thickness in
sexually mature boars.